Railway car cushioning device

ABSTRACT

A hydraulic cushioning device positioned between the underframe and sliding center sill of a railway car to absorb impact forces exerted against either end of the railway car. The hydraulic cushioning device includes a single acting outer fluid cylinder having a metering piston mounted therein with a piston rod secured to one face of the metering piston and extending from one end of the cylinder. An inner fluid cylinder is secured to the opposite face of the metering piston and extends through the other end of the outer cylinder. The inner cylinder includes a freely floating piston dividing the inner cylinder into an outer gas return chamber and an inner hydraulic fluid chamber. A tapered rib secured to the inner surface of the outer cylinder is received within a slot in the metering piston to form a metering orifice therebetween. Impact forces are transmitted from the sliding sill to the cushioning device to extend the piston rod and cylinder upon travel of the sliding sill in either direction thereby to provide an extension of the cushioning device upon the exerting of impact forces from either end of the railway car.

United States Patent [191 Carle Oct. 21, 1975 RAILWAY CAR CUSHIONING DEVICE [75] Inventor: Ross G. Carle, Houston, Tex.

- [73] Assignee: ACF Industries, Incorporated, New

York, NY.

[22] Filed: Nov. 7, 1974 [21] Appl. No.: 521,702

[52] US. Cl. 213/8; 188/316; 213/43; 267/64 R [51] Int. Cl. B61G 9/16 [58] Field of Search 213/8, 43; 267/64 R, 65 R; 188/313, 316

Primary ExaminerM. Henson Wood, Jr. Assistant ExaminerMichael Mar Attorney, Agent, or FirmEugene N. Riddle [57] ABSTRACT A hydraulic cushioning device positioned between the underframe and sliding center sill of a railway car to absorb impact forces exerted against either end of the railway car. The hydraulic cushioning device includes a single acting outer fluid cylinder having a metering piston mounted therein with a piston rod secured to one face of the metering piston and extending from one end of the cylinder. An inner fluid cylinder is secured to the opposite face of the metering piston and extends through the other end of the outer cylinder. The inner cylinder includes a freely floating piston dividing the inner cylinder into an outer gas return chamber and an inner hydraulic fluid chamber. A tapered rib secured to the inner surface of the outer cylinder is received within a slot in the metering piston to form a metering orifice therebetween. Impact forces are transmitted from the sliding sill to the cushioning device to extend the piston rod and cylinder upon travel of the sliding sill in either direction thereby to provide an extension of the cushioning device upon the exerting of impact forces from either end of the railway car.

7 Claims, 8 Drawing Figures U.S. Patent Oct. 21, 1975 Sheet10f3 3,913,748

US. Patent Oct. 21, 1975 Sheet 2 of3 3,913,748

vv .97 w n 0* vv vm Ln W M000 00000 0 0 A v mat US. Patent 0a. 21, 1975 Sheet 3 of3 3,913,748

RAILWAY CAR CUSHIONING DEVICE BACKGROUND OF THE INVENTION I-leretofore, such as illustrated in US. Pat. No. 3,776,391 dated Dec. 4, 1973 railway car cushioning devices have been positioned between the fixed underframe and sliding center sill and a piston rod has extended from one end of the cushioning device for pulling or tensioning of the piston rod upon movement of the sliding sill in either direction upon impact forces being exerted against the railway car from either end. Thus, a single acting center of car cushioning device has been employed heretofore in which the operating or piston rod is placed in tension upon movement of the sliding sill in either direction of travel. However, the piston rod and piston have been returned to their original or neutral position by a coil compression spring after the impact forces have been dissipated by metering of hydraulic fluid. The metering of the hydraulic fluid has been accomplished heretofore with a metering pin and orifice plate combination, or by providing metering openings in an inner cylinder for the metering of hydraulic fluid into an annular area formed between inner and outer concentric cylinders.

BRIEF DESCRIPTION OF PRESENT INVENTION The present invention is directed to a hydraulic cushioning device positioned between the underframe and sliding center sill of a railway car to absorb impact forces exerted against either end of the railway car. The hydraulic cushioning device includes a single acting fluid cylinder having a metering piston mounted therein and a piston rod secured to one face of the metering piston and extending from one end of the cylinder. Means on the sliding center sill and on the fixed center sill are positioned between the outer cylinder and an abutment secured to the extending end of the piston rod for extending the piston rod and cylinder so that the piston rod is placed under tension regardless of the direction of the impact forces exerted against the railway car. An inner hydraulic fluid cylinder is secured to and extends from the opposite face of the metering piston through the other end of the outer cylinder. The inner cylinder includes a freely floating piston which separates the inner cylinder into an outer gas return chamber and an inner hydraulic fluid chamber. A compressible fluid is placed in the gas return chamber and a relatively incompressible liquid is placed in the hydraulic fluid chamber. To provide metering of the hydraulic fluid, a tapered rib is mounted within and secured to the inner surface defining the outer cylinder and a slot in the metering piston receives the rib thereby to provide a metering orifice between the rib and the metering piston. The hydraulic fluid after being metered past the metering piston is received within the inner cylinder through ports extending through the wall of the inner cylinder and hydraulic fluid acts against the adjacent face of the floating piston to move the floating piston in a direction for compressing the compressible fluid in the outer gas return chamber.

An advantage of having a single acting hydraulic cushioning device in which the piston rod is placed in tension upon exertion of any impact forces is that the pressurizing of the unit by inserting a gaseous fluid, such as nitrogen, into the gas return chamber formed in the inner cylinder results in a contraction of the cushioning unit. Therefore, the unit may be pressurized prior to assembly within the railway car since the unit is in its contracted position after pressurized. The pressurizing of the unit prior to assembly within the railway car is relatively simple and may be accomplished in a minimum of time.

The invention accordingly comprises the constructions hereinafter described, the scope of the invention being illustrated in the following claims.

In the accompanying drawings in which one of various possible embodiments of the invention is illustrated:

FIG. 1 is a perspective of the hydraulic cushioning device comprising the present invention in position between the underframe and sliding center sill of a railway car with certain parts broken away;

FIG. 2 is a longitudinal sectional view of the hydraulic cushioning device shown in FIG. I removed from the railway car;

FIG. 3 is a top plan of the railway cushioning device shown in FIGS. 1 and 2 with portions of the railway car underframe and sliding center sill indicated in section;

FIG. 4 is a section taken generally along line 4-4 of FIG. 3; I

FIG. 5 is a section taken generally along line 55 of FIG. 3;

FIG. 6 is a plan view with certain parts broken away illustrating the hydraulic cushioning device in a neutral position;

FIG. 7 is a plan view similar to FIG. 6 but illustrating the hydraulic cushioning device in an extended position after being impacted from the left; and

FIG. 8 is a plan view similar to FIG. 6 but showing the hydraulic cushioning device in its position after being impacted from the right.

Referring now to the drawings for a better understanding of the invention, a railway car underframe is generally indicated 10 and has a fixed center sill structure comprising a pair of spaced fixed center sill members 12 generally channel-shaped in cross section. Each sill member 12 has a web 14 and upper and lower flanges l6 and 18. A pair of spaced channel-shaped side sills 20 are provided along the outer sides of the underframe and cross bearer members generally indicated 22 and cross ties 24 are secured between side sills 20 and sill members 12. Mounted between fixed sill members 12 for sliding movement is a sliding center sill structure generally indicated 26 having a pair of spaced sides 28, a horizontalweb 32 between sides 28, and

lower flanges 30.

Mounted within sliding center sill 26 is a hydraulic cushioning device generally indicated 34 comprising the present invention. To support hydraulic cushioning device 34 within center sill 26, a lower horizontal support plate 36 is secured by suitable nut and bolt combinations 38 to lower flanges 18 of fixed sill members 12.

A second support plate 40 extends between and is secured to flanges 18 by nut and bolt combinations 42. Secured to lower support plate 36 are a pair of spaced stops or abutments 44. Secured to the inner surface of sides 28 of sliding center sill 26 are a pair of spaced stops or abutments 46 which move with sliding center sill 26. Impact forces are transmitted to center sill 12 from suitable couplers (not shown) carried by and mounted within the ends of sliding center sill 12.

Referring now to hydraulic cushioning device 34 forming this invention, an outer cylinder 50 forms a high pressure hydraulic fluid chamber 52 and has a tapered rib 54 secured to its inner wall. End members 56 and 58 are secured to cylinder 50 by suitable studs 60. Mounted within chamber 52 of cylinder 50 for longitudinal movement is a metering piston 62 having a slot 64 as shown in FIG. receiving tapered rib 54 to form a metering orifice 66 between tapered rib 54 and slot 64.

Secured to an end of metering piston 62 for movement therewith is an inner cylinder 68 having a plurality of parts 70 therein. A freely floating piston 72 is mounted within inner cylinder 68 for movement and separates a hydraulic low pressure fluid chamber 74 and a variable volume gas chamber 76. A gas, such as nitrogen or the like, may be inserted within variable volume chamber 76 through fitting 78 and may be initially pressurized to around two hundred (200) psi for example. Inner cylinder 68 extends through a suitable opening in end member 58 and a packing 80 is arranged about cylinder 68 to prevent leakage of hydraulic fluid. Hydraulic fluid which is metered through orifice 66 upon movement of metering piston 62 is transmitted or flows through parts 70 into the low pressure hydraulic fluid chamber 74 to move floating piston 72 outwardly of chamber 52 for pressurizing gas within gas chamber 76. The pressurized gas in chamber 76 after the impact forces have been dissipated will return or urge floating piston 72 to the left as viewed in FIGS. 7 and 8 for contraction of cushioning unit 12.

Extending from the face of piston 62 opposite inner cylinder 68 is a piston rod 82 extending through a suitable opening in end member 56 and having a packing 84 about piston rod 82 to prevent leakage of fluid from chamber 52. Secured to the extending end of piston rod 82 is an annular flanged extension 86 forming an abutment. Flanged extension 86 engages one end of stops 44 and 46 and end member 56 of cylinder 50 engages the opposite ends of stops 44 and 46.

For assembly of hydraulic cushioning device 34 within underframe 10, cushioning device 34 is positioned on support plate 36 having stops 44 secured thereto with stops 44 being positioned between cylin' der 50 and extension 86. Then cushioning device 34 is pressurized with gas by connecting a gas supply, such as nitrogen, to fitting 78 for pressurizing chamber 76. After pressurizing of chamber 76, cushioning device 34 is in its retracted position on support plate 36 and is inserted within sliding center sill 26 with stops 46 positioned between extension 86 and end cap 56 of outer cylinder 50. Support plate 36 is then bolted to flanges 18 of fixed center sill members 12. Next, support plate 40 is bolted to flanges 18 of fixed center sill members 12.

Referring to FIG. 1, oversolid stops 88 are secured to sliding center sill 26 and prevent piston 62 from engaging end member 56 upon the exertion ofimpact forces against center sill 26. Stops 88 will engage either stop 90 or stop 92 before piston 62 bottoms out against end member 56. Tapered rib or ramp 54 and metering orifice 66 are sized so that stops 88 will not normally engage stops 90 and 92 but in the event of a malfunctioning of unit 34, stops 90 and 92 will prevent damage to unit 34 by contact with stops 88.

In operation, and referring to FIGS. 6-8, FIG. 6 illustrates hydraulic cushioning unit 34 in its neutral position prior to an impact against sliding center sill 26. Upon an impact force being exerted against sliding center sill 26 from the left as viewed in FIG. 7, stops 46 in engagement with end member 56 move cylinder 50 to the right while stops 44 retain extension 86 and piston 62 in position. Hydraulic fluid is metered through metering orifice 66 upon movement of cylinder 50 and then flows through ports to variable volume chamber 74 moving floating piston 72 to the right for pressurizing fluid within gas chamber 76 and extending cushioning unit 34. After the impact forces have been dissipated, the pressurized gas in chamber 76 returns cushioning unit 34 to its retracted neutral position shown in FIG. 6.

Upon an impact force beingexerted against sliding center sill 26 from the right as viewed in FIG. 8, sliding sill 26 moves to the left and stops 46 engage extension 86 while. stops 44 retain cylinder 50 thereby to extend cushioning unit 34. The movement of piston rod 82 and metering piston 62 to the left results in hydraulic fluid being metered through metering orifice 66 and then flowing through ports 70 into variable volume chamber 74 to pressurize gas within chamber 76. The pressurized gas within chamber 76 after the dissipation of the impact forces returns metering piston 62 and piston rod 82 to the retracted neutral position of cushioning unit 1 34 shown in FIG. 6. Thus, single acting cushioning unit I 34 is moved to an extended position and piston rod 82 said cushioning unit comprising an outer high pressure hydraulic fluid cylinder, a metering piston mounted within said outer cylinder, a piston rod secured to one side of the metering piston and having an end portion extending through an end of the cylinder outwardly thereof, means on said sliding sill engaging said end portion in one direction of sill travel to extend the piston rod relative to the outer cylinder and means on said sliding sill engaging the outer cylinder in the opposite direction of sill travel to extend the outer cylinder relative to the piston rod, means on said fixed sill restraining movement of said outer cylinder in said one direction of sill travel and means on said fixed sill restraining.

movement of said piston rod in said opposite direction of sill travel, an inner low pressure hydraulic fluid cylinder secured to the other side of the metering piston and i extending through the opposite end of the outer cylin der outwardly thereof, said inner cylinder having a freely floating piston therein dividing said inner cylinder into a variable volume inner hydraulic fluid chamber and an outer variable volume gas return chamber, and a metering opening formed by the metering piston to permit a flow of metered fluid from one side. of the 1 metering piston to the other side thereof, said inner cylinder having port means therein to receive the metered fluid upon relative extended movement between the outer cylinder and piston rod, and said floating piston upon said relative extended movement pressurizing the gas within the gas return chamber for return of the cushioning unit to neutral position after impactforces have been dissipated.

2. In a railway car as set forth in claim 1, said metering piston having a groove therein adjacent its outer circumference, and a tapered rib is secured to the inner wall of the outer cylinder and is received by said groove to form said metering opening between the rib and groove.

3. In a railway car as set forth in claim 1, said fixed sill comprising a pair of sill members having lower generally horizontal flanges, a support plate beneath the cushioning unit secured to said flanges and having a pair of spaced vertically extending members secured thereto extending within the sliding sill adjacent the outer cylinder and piston rod, said vertically extending members forming said means on the fixed sill to restrain movement of said outer cylinder in one direction of sill travel and restrain movement of said piston rod in an opposite direction of sill travel.

4. In a railway car as set forth in claim 1, an extension on the end portion of said piston rod, and said means on said sliding sill comprise abutments secured to the inner surface of the sliding sill between the extension and said outer cylinder for engaging the extension in one direction of sill travel and engaging its outer cylinder in the opposite direction of sill travel.v

5. A single acting hydraulic fluid cushioning unit positioned between an underframe fixed center sill and a sliding center sill of a railway car comprising, in combination: an outer high pressure hydraulic fluid cylinder, a metering piston mounted within said outer cylinder adjacent one end of the outer cylinder when in a neutral position, a piston rod secured to the metering piston and extending through the opposite end of the outer cylinder, said piston rod having an extending free end portion thereof outwardly of the outer cylinder and a lateral extension on said free end portion, stops on the fixed sill for engaging the extension and the outer cylinder to restrain movement of the outer cylinder in one direction of sill travel and to restrain movement of the extension and piston rod in the opposite direction of sill travel, stops on the sliding sill for engaging the extension and outer cylinder to move the fluid cylinder in one direction of sill travel and to move the extension and piston rod in the opposite direction of sill travel, an inner low pressure hydraulic fluid cylinder secured to said metering piston on the side thereof opposite said piston rod and extending through said one end of the cylinder, said inner cylinder having a freely floating piston therein dividing said inner cylinder into an inner hydraulic fluid chamber and an outer gas return chamber adapted to secure a compressible gas therein, and a metering opening formed by the metering piston to permit a flow of metered fluid from one side of the metering piston to the other side thereof, said inner cylinder having port means therein to receive the metered fluid upon relative extended movement between the cylinder and piston rod from the neutral retracted position of the cushioning unit.

6. The single acting hydraulic fluid cushioning unit as set forth in claim 5 wherein said metering piston has a groove therein adjacent its outer circumference, and a tapered rib is secured to the inner wall of the outer cylinder and is received by said groove to form said metering opening between the rib and groove.

7. A single acting hydraulic fluid cushioning unit adapted to be positioned between an underframe fixed center sill and a sliding sill of a railway car comprising: an outer high pressure hydraulic fluid cylinder, a metering piston mounted within said outer cylinder, a piston rod secured to one side of the metering piston and having an end portion extending through an end of the outer cylinder outwardly thereof, an inner low pressure hydraulic fluid cylinder secured to the other side of the metering piston and extending through the opposite end of the outer cylinder outwardly thereof, said inner cylinder having a freely floating piston therein dividing said inner cylinder into a variable volume inner hydraulic fluid chamber and an outer variable volume gas return chamber, and a metering opening formed adjacent the outer circumference of the metering piston to permit a flow of metered fluid from one side of the metering piston to the other side thereof, said inner cylinder having ports therein to receive the metered fluid upon relative extended movement between the outer cylinder and piston rod, and said floating piston upon said relative extended movement pressurizing the gas within the gas return chamber for return of the cushioning unit to neutral position. 

1. In a railway car, an underframe having a fixed center sill, a sliding center sill mounted within the fixed center sill for relative movement upon impact forces exerted against the sliding sill, a single acting hydraulic fluid cushioning unit mounted within the sliding sill, said cushioning unit comprising an outer high pressure hydraulic fluid cylinder, a metering piston mounted within said outer cylinder, a piston rod secured to one side of the metering piston and having an end portion extending through an end of the cylinder outwardly thereof, means on said sliding sill engaging said end portion in one direction of sill travel to extend the piston rod relative to the outer cylinder and means on said sliding sill engaging the outer cylinder in the opposite direction of sill travel to extend the outer cylinder relative to the piston rod, means on said fixed sill restraining movement of said outer cylinder in said one direction of sill travel and means on said fixed sill restraining movement of said piston rod in said opposite direction of sill travel, an inner low pressure hydraulic fluid cylinder secured to the other side of the metering piston and extending through the opposite end of the outer cylinder outwardly thereof, said inner cylinder having a freely floating piston therein dividing said inner cylinder into a variable volume inner hydraulic fluid chamber and an outer variable volume gas return chamber, and a metering opening formed by the metering piston to permit a flow of metered fluid from one side of the metering piston to the other side thereof, said inner cylinder having port means therein to receive the metered fluid upon relative extended movement between the outer cylinder and piston rod, and said floating piston upon said relative extended movement pressurizing the gas within the gas return chamber for return of the cushioning unit to neutral position after impact forces have been dissipated.
 2. In a railway car as set forth in claim 1, said metering piston having a groove therein adjacent its outer circumference, and a tapered rib is secured to the inner wall of the outer cylinder and is received by said groove to form said metering opening between the rib and groove.
 3. In a railway car as set forth in claim 1, said fixed sill comprising a pair of sill members having lower generally horizontal flanges, a support plate beneath the cushioning unit secured to said flanges and having a pair of spaced vertically extending members secured thereto extending within the sliding sill adjacent the outer cylinder and piston rod, said vertically extending members forming said means on the fixed sill to restrain mOvement of said outer cylinder in one direction of sill travel and restrain movement of said piston rod in an opposite direction of sill travel.
 4. In a railway car as set forth in claim 1, an extension on the end portion of said piston rod, and said means on said sliding sill comprise abutments secured to the inner surface of the sliding sill between the extension and said outer cylinder for engaging the extension in one direction of sill travel and engaging its outer cylinder in the opposite direction of sill travel.
 5. A single acting hydraulic fluid cushioning unit positioned between an underframe fixed center sill and a sliding center sill of a railway car comprising, in combination: an outer high pressure hydraulic fluid cylinder, a metering piston mounted within said outer cylinder adjacent one end of the outer cylinder when in a neutral position, a piston rod secured to the metering piston and extending through the opposite end of the outer cylinder, said piston rod having an extending free end portion thereof outwardly of the outer cylinder and a lateral extension on said free end portion, stops on the fixed sill for engaging the extension and the outer cylinder to restrain movement of the outer cylinder in one direction of sill travel and to restrain movement of the extension and piston rod in the opposite direction of sill travel, stops on the sliding sill for engaging the extension and outer cylinder to move the fluid cylinder in one direction of sill travel and to move the extension and piston rod in the opposite direction of sill travel, an inner low pressure hydraulic fluid cylinder secured to said metering piston on the side thereof opposite said piston rod and extending through said one end of the cylinder, said inner cylinder having a freely floating piston therein dividing said inner cylinder into an inner hydraulic fluid chamber and an outer gas return chamber adapted to secure a compressible gas therein, and a metering opening formed by the metering piston to permit a flow of metered fluid from one side of the metering piston to the other side thereof, said inner cylinder having port means therein to receive the metered fluid upon relative extended movement between the cylinder and piston rod from the neutral retracted position of the cushioning unit.
 6. The single acting hydraulic fluid cushioning unit as set forth in claim 5 wherein said metering piston has a groove therein adjacent its outer circumference, and a tapered rib is secured to the inner wall of the outer cylinder and is received by said groove to form said metering opening between the rib and groove.
 7. A single acting hydraulic fluid cushioning unit adapted to be positioned between an underframe fixed center sill and a sliding sill of a railway car comprising: an outer high pressure hydraulic fluid cylinder, a metering piston mounted within said outer cylinder, a piston rod secured to one side of the metering piston and having an end portion extending through an end of the outer cylinder outwardly thereof, an inner low pressure hydraulic fluid cylinder secured to the other side of the metering piston and extending through the opposite end of the outer cylinder outwardly thereof, said inner cylinder having a freely floating piston therein dividing said inner cylinder into a variable volume inner hydraulic fluid chamber and an outer variable volume gas return chamber, and a metering opening formed adjacent the outer circumference of the metering piston to permit a flow of metered fluid from one side of the metering piston to the other side thereof, said inner cylinder having ports therein to receive the metered fluid upon relative extended movement between the outer cylinder and piston rod, and said floating piston upon said relative extended movement pressurizing the gas within the gas return chamber for return of the cushioning unit to neutral position. 